Removed redundant numbered parameters from str.format().

Since Python 2.7 and 3.1, "{0} {1}" is equivalent to "{} {}".

24 files changed, 72 insertions, 72 deletions

diff --git a/django/contrib/admin/helpers.py b/django/contrib/admin/helpers.py
index a7c95f5046..0383f1c72a 100644
--- a/django/contrib/admin/helpers.py
+++ b/django/contrib/admin/helpers.py
@@ -178,7 +178,7 @@ class AdminReadonlyField(object):
         if not self.is_first:
             attrs["class"] = "inline"
         label = self.field['label']
-        return format_html('<label{0}>{1}:</label>',
+        return format_html('<label{}>{}:</label>',
                            flatatt(attrs),
                            capfirst(force_text(label)))
 
diff --git a/django/contrib/admin/templatetags/admin_list.py b/django/contrib/admin/templatetags/admin_list.py
index 702f1166fe..544c5503ec 100644
--- a/django/contrib/admin/templatetags/admin_list.py
+++ b/django/contrib/admin/templatetags/admin_list.py
@@ -34,9 +34,9 @@ def paginator_number(cl, i):
     if i == DOT:
         return '... '
     elif i == cl.page_num:
-        return format_html('<span class="this-page">{0}</span> ', i + 1)
+        return format_html('<span class="this-page">{}</span> ', i + 1)
     else:
-        return format_html('<a href="{0}"{1}>{2}</a> ',
+        return format_html('<a href="{}"{}>{}</a> ',
                            cl.get_query_string({PAGE_VAR: i}),
                            mark_safe(' class="end"' if i == cl.paginator.num_pages - 1 else ''),
                            i + 1)
@@ -117,13 +117,13 @@ def result_headers(cl):
                 # Not sortable
                 yield {
                     "text": text,
-                    "class_attrib": format_html(' class="column-{0}"', field_name),
+                    "class_attrib": format_html(' class="column-{}"', field_name),
                     "sortable": False,
                 }
                 continue
 
         # OK, it is sortable if we got this far
-        th_classes = ['sortable', 'column-{0}'.format(field_name)]
+        th_classes = ['sortable', 'column-{}'.format(field_name)]
         order_type = ''
         new_order_type = 'asc'
         sort_priority = 0
@@ -168,14 +168,14 @@ def result_headers(cl):
             "url_primary": cl.get_query_string({ORDER_VAR: '.'.join(o_list_primary)}),
             "url_remove": cl.get_query_string({ORDER_VAR: '.'.join(o_list_remove)}),
             "url_toggle": cl.get_query_string({ORDER_VAR: '.'.join(o_list_toggle)}),
-            "class_attrib": format_html(' class="{0}"', ' '.join(th_classes)) if th_classes else '',
+            "class_attrib": format_html(' class="{}"', ' '.join(th_classes)) if th_classes else '',
         }
 
 
 def _boolean_icon(field_val):
     icon_url = static('admin/img/icon-%s.gif' %
                       {True: 'yes', False: 'no', None: 'unknown'}[field_val])
-    return format_html('<img src="{0}" alt="{1}" />', icon_url, field_val)
+    return format_html('<img src="{}" alt="{}" />', icon_url, field_val)
 
 
 def items_for_result(cl, result, form):
@@ -249,15 +249,15 @@ def items_for_result(cl, result, form):
                 value = result.serializable_value(attr)
                 result_id = escapejs(value)
                 link_or_text = format_html(
-                    '<a href="{0}"{1}>{2}</a>',
+                    '<a href="{}"{}>{}</a>',
                     url,
                     format_html(
                         ' onclick="opener.dismissRelatedLookupPopup(window, '
-                        '&#39;{0}&#39;); return false;"', result_id
+                        '&#39;{}&#39;); return false;"', result_id
                     ) if cl.is_popup else '',
                     result_repr)
 
-            yield format_html('<{0}{1}>{2}</{3}>',
+            yield format_html('<{}{}>{}</{}>',
                               table_tag,
                               row_class,
                               link_or_text,
@@ -271,9 +271,9 @@ def items_for_result(cl, result, form):
                     form[cl.model._meta.pk.name].is_hidden)):
                 bf = form[field_name]
                 result_repr = mark_safe(force_text(bf.errors) + force_text(bf))
-            yield format_html('<td{0}>{1}</td>', row_class, result_repr)
+            yield format_html('<td{}>{}</td>', row_class, result_repr)
     if form and not form[cl.model._meta.pk.name].is_hidden:
-        yield format_html('<td>{0}</td>', force_text(form[cl.model._meta.pk.name]))
+        yield format_html('<td>{}</td>', force_text(form[cl.model._meta.pk.name]))
 
 
 class ResultList(list):
diff --git a/django/contrib/admin/utils.py b/django/contrib/admin/utils.py
index d6756332d3..20e3561e76 100644
--- a/django/contrib/admin/utils.py
+++ b/django/contrib/admin/utils.py
@@ -142,7 +142,7 @@ def get_deleted_objects(objs, opts, user, admin_site, using):
             if not user.has_perm(p):
                 perms_needed.add(opts.verbose_name)
             # Display a link to the admin page.
-            return format_html('{0}: <a href="{1}">{2}</a>',
+            return format_html('{}: <a href="{}">{}</a>',
                                capfirst(opts.verbose_name),
                                admin_url,
                                obj)
diff --git a/django/contrib/admin/widgets.py b/django/contrib/admin/widgets.py
index 3b14087176..c7312b9a46 100644
--- a/django/contrib/admin/widgets.py
+++ b/django/contrib/admin/widgets.py
@@ -87,7 +87,7 @@ class AdminSplitDateTime(forms.SplitDateTimeWidget):
         forms.MultiWidget.__init__(self, widgets, attrs)
 
     def format_output(self, rendered_widgets):
-        return format_html('<p class="datetime">{0} {1}<br />{2} {3}</p>',
+        return format_html('<p class="datetime">{} {}<br />{} {}</p>',
                            _('Date:'), rendered_widgets[0],
                            _('Time:'), rendered_widgets[1])
 
@@ -95,9 +95,9 @@ class AdminSplitDateTime(forms.SplitDateTimeWidget):
 class AdminRadioFieldRenderer(RadioFieldRenderer):
     def render(self):
         """Outputs a <ul> for this set of radio fields."""
-        return format_html('<ul{0}>\n{1}\n</ul>',
+        return format_html('<ul{}>\n{}\n</ul>',
                            flatatt(self.attrs),
-                           format_html_join('\n', '<li>{0}</li>',
+                           format_html_join('\n', '<li>{}</li>',
                                             ((force_text(w),) for w in self)))
 
 
@@ -325,7 +325,7 @@ class AdminURLFieldWidget(forms.URLInput):
             value = force_text(self._format_value(value))
             final_attrs = {'href': smart_urlquote(value)}
             html = format_html(
-                '<p class="url">{0} <a{1}>{2}</a><br />{3} {4}</p>',
+                '<p class="url">{} <a{}>{}</a><br />{} {}</p>',
                 _('Currently:'), flatatt(final_attrs), value,
                 _('Change:'), html
             )
diff --git a/django/contrib/auth/forms.py b/django/contrib/auth/forms.py
index c54a0862ed..86cfa291c9 100644
--- a/django/contrib/auth/forms.py
+++ b/django/contrib/auth/forms.py
@@ -44,12 +44,12 @@ class ReadOnlyPasswordHashWidget(forms.Widget):
                     "Invalid password format or unknown hashing algorithm."))
             else:
                 summary = format_html_join('',
-                                           "<strong>{0}</strong>: {1} ",
+                                           "<strong>{}</strong>: {} ",
                                            ((ugettext(key), value)
                                             for key, value in hasher.safe_summary(encoded).items())
                                            )
 
-        return format_html("<div{0}>{1}</div>", flatatt(final_attrs), summary)
+        return format_html("<div{}>{}</div>", flatatt(final_attrs), summary)
 
 
 class ReadOnlyPasswordHashField(forms.Field):
diff --git a/django/contrib/gis/maps/google/gmap.py b/django/contrib/gis/maps/google/gmap.py
index 82e1eeeb24..4694996283 100644
--- a/django/contrib/gis/maps/google/gmap.py
+++ b/django/contrib/gis/maps/google/gmap.py
@@ -121,17 +121,17 @@ class GoogleMap(object):
     @property
     def body(self):
         "Returns HTML body tag for loading and unloading Google Maps javascript."
-        return format_html('<body {0} {1}>', self.onload, self.onunload)
+        return format_html('<body {} {}>', self.onload, self.onunload)
 
     @property
     def onload(self):
         "Returns the `onload` HTML <body> attribute."
-        return format_html('onload="{0}.{1}_load()"', self.js_module, self.dom_id)
+        return format_html('onload="{}.{}_load()"', self.js_module, self.dom_id)
 
     @property
     def api_script(self):
         "Returns the <script> tag for the Google Maps API javascript."
-        return format_html('<script src="{0}{1}" type="text/javascript"></script>',
+        return format_html('<script src="{}{}" type="text/javascript"></script>',
                            self.api_url, self.key)
 
     @property
@@ -142,18 +142,18 @@ class GoogleMap(object):
     @property
     def scripts(self):
         "Returns all <script></script> tags required with Google Maps JavaScript."
-        return format_html('{0}\n  <script type="text/javascript">\n//<![CDATA[\n{1}//]]>\n  </script>',
+        return format_html('{}\n  <script type="text/javascript">\n//<![CDATA[\n{}//]]>\n  </script>',
                            self.api_script, mark_safe(self.js))
 
     @property
     def style(self):
         "Returns additional CSS styling needed for Google Maps on IE."
-        return format_html('<style type="text/css">{0}</style>', self.vml_css)
+        return format_html('<style type="text/css">{}</style>', self.vml_css)
 
     @property
     def xhtml(self):
         "Returns XHTML information needed for IE VML overlays."
-        return format_html('<html xmlns="http://www.w3.org/1999/xhtml" {0}>', self.xmlns)
+        return format_html('<html xmlns="http://www.w3.org/1999/xhtml" {}>', self.xmlns)
 
     @property
     def icons(self):
diff --git a/django/contrib/sessions/tests.py b/django/contrib/sessions/tests.py
index fe74c3f255..6679899a34 100644
--- a/django/contrib/sessions/tests.py
+++ b/django/contrib/sessions/tests.py
@@ -601,7 +601,7 @@ class SessionMiddlewareTests(unittest.TestCase):
         # A deleted cookie header looks like:
         #  Set-Cookie: sessionid=; expires=Thu, 01-Jan-1970 00:00:00 GMT; Max-Age=0; Path=/
         self.assertEqual(
-            'Set-Cookie: {0}=; expires=Thu, 01-Jan-1970 00:00:00 GMT; '
+            'Set-Cookie: {}=; expires=Thu, 01-Jan-1970 00:00:00 GMT; '
             'Max-Age=0; Path=/'.format(settings.SESSION_COOKIE_NAME),
             str(response.cookies[settings.SESSION_COOKIE_NAME])
         )
diff --git a/django/forms/forms.py b/django/forms/forms.py
index 3f6a876832..e68542e12a 100644
--- a/django/forms/forms.py
+++ b/django/forms/forms.py
@@ -645,7 +645,7 @@ class BoundField(object):
         # Translators: If found as last label character, these punctuation
         # characters will prevent the default label_suffix to be appended to the label
         if label_suffix and contents and contents[-1] not in _(':?.!'):
-            contents = format_html('{0}{1}', contents, label_suffix)
+            contents = format_html('{}{}', contents, label_suffix)
         widget = self.field.widget
         id_ = widget.attrs.get('id') or self.auto_id
         if id_:
@@ -659,7 +659,7 @@ class BoundField(object):
                 else:
                     attrs['class'] = self.form.required_css_class
             attrs = flatatt(attrs) if attrs else ''
-            contents = format_html('<label{0}>{1}</label>', attrs, contents)
+            contents = format_html('<label{}>{}</label>', attrs, contents)
         else:
             contents = conditional_escape(contents)
         return mark_safe(contents)
diff --git a/django/forms/utils.py b/django/forms/utils.py
index 7d4cd90b57..19c27f9b8c 100644
--- a/django/forms/utils.py
+++ b/django/forms/utils.py
@@ -39,8 +39,8 @@ def flatatt(attrs):
             key_value_attrs.append((attr, value))
 
     return (
-        format_html_join('', ' {0}="{1}"', sorted(key_value_attrs)) +
-        format_html_join('', ' {0}', sorted(boolean_attrs))
+        format_html_join('', ' {}="{}"', sorted(key_value_attrs)) +
+        format_html_join('', ' {}', sorted(boolean_attrs))
     )
 
 
@@ -61,8 +61,8 @@ class ErrorDict(dict):
         if not self:
             return ''
         return format_html(
-            '<ul class="errorlist">{0}</ul>',
-            format_html_join('', '<li>{0}{1}</li>', ((k, force_text(v)) for k, v in self.items()))
+            '<ul class="errorlist">{}</ul>',
+            format_html_join('', '<li>{}{}</li>', ((k, force_text(v)) for k, v in self.items()))
         )
 
     def as_text(self):
@@ -110,9 +110,9 @@ class ErrorList(UserList, list):
             return ''
 
         return format_html(
-            '<ul class="{0}">{1}</ul>',
+            '<ul class="{}">{}</ul>',
             self.error_class,
-            format_html_join('', '<li>{0}</li>', ((force_text(e),) for e in self))
+            format_html_join('', '<li>{}</li>', ((force_text(e),) for e in self))
         )
 
     def as_text(self):
diff --git a/django/forms/widgets.py b/django/forms/widgets.py
index 7e3c8f3dca..de75b35932 100644
--- a/django/forms/widgets.py
+++ b/django/forms/widgets.py
@@ -53,7 +53,7 @@ class Media(object):
     def render_js(self):
         return [
             format_html(
-                '<script type="text/javascript" src="{0}"></script>',
+                '<script type="text/javascript" src="{}"></script>',
                 self.absolute_path(path)
             ) for path in self._js
         ]
@@ -64,7 +64,7 @@ class Media(object):
         media = sorted(self._css.keys())
         return chain(*[[
             format_html(
-                '<link href="{0}" type="text/css" media="{1}" rel="stylesheet" />',
+                '<link href="{}" type="text/css" media="{}" rel="stylesheet" />',
                 self.absolute_path(path), medium
             ) for path in self._css[medium]
         ] for medium in media])
@@ -252,7 +252,7 @@ class Input(Widget):
         if value != '':
             # Only add the 'value' attribute if a value is non-empty.
             final_attrs['value'] = force_text(self._format_value(value))
-        return format_html('<input{0} />', flatatt(final_attrs))
+        return format_html('<input{} />', flatatt(final_attrs))
 
 
 class TextInput(Input):
@@ -315,7 +315,7 @@ class MultipleHiddenInput(HiddenInput):
                 # An ID attribute was given. Add a numeric index as a suffix
                 # so that the inputs don't all have the same ID attribute.
                 input_attrs['id'] = '%s_%s' % (id_, i)
-            inputs.append(format_html('<input{0} />', flatatt(input_attrs)))
+            inputs.append(format_html('<input{} />', flatatt(input_attrs)))
         return mark_safe('\n'.join(inputs))
 
     def value_from_datadict(self, data, files, name):
@@ -429,7 +429,7 @@ class Textarea(Widget):
         if value is None:
             value = ''
         final_attrs = self.build_attrs(attrs, name=name)
-        return format_html('<textarea{0}>\r\n{1}</textarea>',
+        return format_html('<textarea{}>\r\n{}</textarea>',
                            flatatt(final_attrs),
                            force_text(value))
 
@@ -478,7 +478,7 @@ class CheckboxInput(Widget):
         if not (value is True or value is False or value is None or value == ''):
             # Only add the 'value' attribute if a value is non-empty.
             final_attrs['value'] = force_text(value)
-        return format_html('<input{0} />', flatatt(final_attrs))
+        return format_html('<input{} />', flatatt(final_attrs))
 
     def value_from_datadict(self, data, files, name):
         if name not in data:
@@ -507,7 +507,7 @@ class Select(Widget):
         if value is None:
             value = ''
         final_attrs = self.build_attrs(attrs, name=name)
-        output = [format_html('<select{0}>', flatatt(final_attrs))]
+        output = [format_html('<select{}>', flatatt(final_attrs))]
         options = self.render_options(choices, [value])
         if options:
             output.append(options)
@@ -525,7 +525,7 @@ class Select(Widget):
                 selected_choices.remove(option_value)
         else:
             selected_html = ''
-        return format_html('<option value="{0}"{1}>{2}</option>',
+        return format_html('<option value="{}"{}>{}</option>',
                            option_value,
                            selected_html,
                            force_text(option_label))
@@ -536,7 +536,7 @@ class Select(Widget):
         output = []
         for option_value, option_label in chain(self.choices, choices):
             if isinstance(option_label, (list, tuple)):
-                output.append(format_html('<optgroup label="{0}">', force_text(option_value)))
+                output.append(format_html('<optgroup label="{}">', force_text(option_value)))
                 for option in option_label:
                     output.append(self.render_option(selected_choices, *option))
                 output.append('</optgroup>')
@@ -579,7 +579,7 @@ class SelectMultiple(Select):
         if value is None:
             value = []
         final_attrs = self.build_attrs(attrs, name=name)
-        output = [format_html('<select multiple="multiple"{0}>', flatatt(final_attrs))]
+        output = [format_html('<select multiple="multiple"{}>', flatatt(final_attrs))]
         options = self.render_options(choices, value)
         if options:
             output.append(options)
@@ -615,12 +615,12 @@ class ChoiceInput(SubWidget):
 
     def render(self, name=None, value=None, attrs=None, choices=()):
         if self.id_for_label:
-            label_for = format_html(' for="{0}"', self.id_for_label)
+            label_for = format_html(' for="{}"', self.id_for_label)
         else:
             label_for = ''
         attrs = dict(self.attrs, **attrs) if attrs else self.attrs
         return format_html(
-            '<label{0}>{1} {2}</label>', label_for, self.tag(attrs), self.choice_label
+            '<label{}>{} {}</label>', label_for, self.tag(attrs), self.choice_label
         )
 
     def is_checked(self):
@@ -631,7 +631,7 @@ class ChoiceInput(SubWidget):
         final_attrs = dict(attrs, type=self.input_type, name=self.name, value=self.choice_value)
         if self.is_checked():
             final_attrs['checked'] = 'checked'
-        return format_html('<input{0} />', flatatt(final_attrs))
+        return format_html('<input{} />', flatatt(final_attrs))
 
     @property
     def id_for_label(self):
@@ -693,7 +693,7 @@ class ChoiceFieldRenderer(object):
             if isinstance(choice_label, (tuple, list)):
                 attrs_plus = self.attrs.copy()
                 if id_:
-                    attrs_plus['id'] += '_{0}'.format(i)
+                    attrs_plus['id'] += '_{}'.format(i)
                 sub_ul_renderer = ChoiceFieldRenderer(name=self.name,
                                                       value=self.value,
                                                       attrs=attrs_plus,
@@ -707,7 +707,7 @@ class ChoiceFieldRenderer(object):
                 output.append(format_html(self.inner_html,
                                           choice_value=force_text(w), sub_widgets=''))
         return format_html(self.outer_html,
-                           id_attr=format_html(' id="{0}"', id_) if id_ else '',
+                           id_attr=format_html(' id="{}"', id_) if id_ else '',
                            content=mark_safe('\n'.join(output)))
 
 
diff --git a/django/template/defaulttags.py b/django/template/defaulttags.py
index 51ddfc9819..c6814983e7 100644
--- a/django/template/defaulttags.py
+++ b/django/template/defaulttags.py
@@ -56,7 +56,7 @@ class CsrfTokenNode(Node):
             if csrf_token == 'NOTPROVIDED':
                 return format_html("")
             else:
-                return format_html("<input type='hidden' name='csrfmiddlewaretoken' value='{0}' />", csrf_token)
+                return format_html("<input type='hidden' name='csrfmiddlewaretoken' value='{}' />", csrf_token)
         else:
             # It's very probable that the token is missing because of
             # misconfiguration, so we raise a warning
@@ -195,7 +195,7 @@ class ForNode(Node):
                     # Check loop variable count before unpacking
                     if num_loopvars != len_item:
                         warnings.warn(
-                            "Need {0} values to unpack in for loop; got {1}. "
+                            "Need {} values to unpack in for loop; got {}. "
                             "This will raise an exception in Django 2.0."
                             .format(num_loopvars, len_item),
                             RemovedInDjango20Warning)
diff --git a/django/utils/html.py b/django/utils/html.py
index 2dc16d5d71..1247849f31 100644
--- a/django/utils/html.py
+++ b/django/utils/html.py
@@ -105,7 +105,7 @@ def format_html_join(sep, format_string, args_generator):
 
     Example:
 
-      format_html_join('\n', "<li>{0} {1}</li>", ((u.first_name, u.last_name)
+      format_html_join('\n', "<li>{} {}</li>", ((u.first_name, u.last_name)
                                                   for u in users))
 
     """
diff --git a/django/utils/log.py b/django/utils/log.py
index 6ced3a4a63..fc350e0b5e 100644
--- a/django/utils/log.py
+++ b/django/utils/log.py
@@ -109,7 +109,7 @@ class AdminEmailHandler(logging.Handler):
                 record.getMessage()
             )
             filter = get_exception_reporter_filter(request)
-            request_repr = '\n{0}'.format(force_text(filter.get_request_repr(request)))
+            request_repr = '\n{}'.format(force_text(filter.get_request_repr(request)))
         except Exception:
             subject = '%s: %s' % (
                 record.levelname,
diff --git a/docs/howto/outputting-csv.txt b/docs/howto/outputting-csv.txt
index d1a778db47..71cb5db036 100644
--- a/docs/howto/outputting-csv.txt
+++ b/docs/howto/outputting-csv.txt
@@ -106,7 +106,7 @@ the assembly and transmission of a large CSV file::
         # Generate a sequence of rows. The range is based on the maximum number of
         # rows that can be handled by a single sheet in most spreadsheet
         # applications.
-        rows = (["Row {0}".format(idx), str(idx)] for idx in range(65536))
+        rows = (["Row {}".format(idx), str(idx)] for idx in range(65536))
         pseudo_buffer = Echo()
         writer = csv.writer(pseudo_buffer)
         response = StreamingHttpResponse((writer.writerow(row) for row in rows),
diff --git a/docs/intro/contributing.txt b/docs/intro/contributing.txt
index b1fb7b0ef6..d305a8bb91 100644
--- a/docs/intro/contributing.txt
+++ b/docs/intro/contributing.txt
@@ -325,7 +325,7 @@ the following ``render`` method after the existing ``__init__`` method::
             value = force_text(self._format_value(value))
             final_attrs = {'href': mark_safe(smart_urlquote(value))}
             html = format_html(
-                '<p class="url">{0} <a {1}>{2}</a><br />{3} {4}</p>',
+                '<p class="url">{} <a {}>{}</a><br />{} {}</p>',
                 _('Currently:'), flatatt(final_attrs), value,
                 _('Change:'), html
             )
@@ -443,7 +443,7 @@ This patch file contains all your changes and should look this:
     +            value = force_text(self._format_value(value))
     +            final_attrs = {'href': mark_safe(smart_urlquote(value))}
     +            html = format_html(
-    +                '<p class="url">{0} <a {1}>{2}</a><br />{3} {4}</p>',
+    +                '<p class="url">{} <a {}>{}</a><br />{} {}</p>',
     +                _('Currently:'), flatatt(final_attrs), value,
     +                _('Change:'), html
     +            )
diff --git a/docs/ref/contrib/admin/index.txt b/docs/ref/contrib/admin/index.txt
index a85993cd2e..fd6d8f5f3a 100644
--- a/docs/ref/contrib/admin/index.txt
+++ b/docs/ref/contrib/admin/index.txt
@@ -590,7 +590,7 @@ subclass::
               color_code = models.CharField(max_length=6)
 
               def colored_name(self):
-                  return format_html('<span style="color: #{0};">{1} {2}</span>',
+                  return format_html('<span style="color: #{};">{} {}</span>',
                                      self.color_code,
                                      self.first_name,
                                      self.last_name)
@@ -647,7 +647,7 @@ subclass::
             color_code = models.CharField(max_length=6)
 
             def colored_first_name(self):
-                return format_html('<span style="color: #{0};">{1}</span>',
+                return format_html('<span style="color: #{};">{}</span>',
                                    self.color_code,
                                    self.first_name)
 
@@ -1060,7 +1060,7 @@ subclass::
                 # line by a linebreak
                 return format_html_join(
                     mark_safe('<br/>'),
-                    '{0}',
+                    '{}',
                     ((line,) for line in instance.get_full_address()),
                 ) or "<span class='errors'>I can't determine this address.</span>"
 
diff --git a/docs/ref/utils.txt b/docs/ref/utils.txt
index b32f0a838b..56e9fb7dce 100644
--- a/docs/ref/utils.txt
+++ b/docs/ref/utils.txt
@@ -605,7 +605,7 @@ escaping HTML.
 
     You should instead use::
 
-        format_html("{0} <b>{1}</b> {2}",
+        format_html("{} <b>{}</b> {}",
                     mark_safe(some_html), some_text, some_other_text)
 
     This has the advantage that you don't need to apply :func:`escape` to each
@@ -627,7 +627,7 @@ escaping HTML.
     ``args_generator`` should be an iterator that returns the sequence of
     ``args`` that will be passed to :func:`format_html`. For example::
 
-        format_html_join('\n', "<li>{0} {1}</li>", ((u.first_name, u.last_name)
+        format_html_join('\n', "<li>{} {}</li>", ((u.first_name, u.last_name)
                                                     for u in users))
 
 .. function:: strip_tags(value)
diff --git a/tests/file_uploads/tests.py b/tests/file_uploads/tests.py
index 4fa75415ec..85363744d8 100644
--- a/tests/file_uploads/tests.py
+++ b/tests/file_uploads/tests.py
@@ -239,7 +239,7 @@ class FileUploadTests(TestCase):
         for name, filename, _ in cases:
             payload.write("\r\n".join([
                 '--' + client.BOUNDARY,
-                'Content-Disposition: form-data; name="{0}"; filename="{1}"',
+                'Content-Disposition: form-data; name="{}"; filename="{}"',
                 'Content-Type: application/octet-stream',
                 '',
                 'Oops.',
@@ -258,7 +258,7 @@ class FileUploadTests(TestCase):
         result = json.loads(response.content.decode('utf-8'))
         for name, _, expected in cases:
             got = result[name]
-            self.assertEqual(expected, got, 'Mismatch for {0}'.format(name))
+            self.assertEqual(expected, got, 'Mismatch for {}'.format(name))
             self.assertLess(len(got), 256,
                             "Got a long file name (%s characters)." % len(got))
 
diff --git a/tests/forms_tests/tests/test_forms.py b/tests/forms_tests/tests/test_forms.py
index 6478116f02..1980e01d73 100644
--- a/tests/forms_tests/tests/test_forms.py
+++ b/tests/forms_tests/tests/test_forms.py
@@ -1384,7 +1384,7 @@ class FormsTestCase(TestCase):
         """
         class CustomWidget(TextInput):
             def render(self, name, value, attrs=None):
-                return format_html(str('<input{0} />'), ' id=custom')
+                return format_html(str('<input{} />'), ' id=custom')
 
         class SampleForm(Form):
             name = CharField(widget=CustomWidget)
diff --git a/tests/forms_tests/tests/tests.py b/tests/forms_tests/tests/tests.py
index d53d030158..0b3d5765a0 100644
--- a/tests/forms_tests/tests/tests.py
+++ b/tests/forms_tests/tests/tests.py
@@ -316,7 +316,7 @@ class EmptyLabelTestCase(TestCase):
             m = f.save()
             self.assertEqual(expected, getattr(m, key))
             self.assertEqual('No Preference',
-                             getattr(m, 'get_{0}_display'.format(key))())
+                             getattr(m, 'get_{}_display'.format(key))())
 
     def test_empty_field_integer(self):
         f = EmptyIntegerLabelChoiceForm()
diff --git a/tests/template_tests/tests.py b/tests/template_tests/tests.py
index 43dac24b92..d58c91f90d 100644
--- a/tests/template_tests/tests.py
+++ b/tests/template_tests/tests.py
@@ -319,12 +319,12 @@ class TemplateRegressionTests(TestCase):
             # When the IfChangeNode stores state at 'self' it stays at '3' and skip the last yielded value below.
             iter2 = iter([1, 2, 3])
             output2 = template.render(Context({'foo': range(3), 'get_value': lambda: next(iter2)}))
-            self.assertEqual(output2, '[0,1,2,3]', 'Expected [0,1,2,3] in second parallel template, got {0}'.format(output2))
+            self.assertEqual(output2, '[0,1,2,3]', 'Expected [0,1,2,3] in second parallel template, got {}'.format(output2))
             yield 3
 
         gen1 = gen()
         output1 = template.render(Context({'foo': range(3), 'get_value': lambda: next(gen1)}))
-        self.assertEqual(output1, '[0,1,2,3]', 'Expected [0,1,2,3] in first template, got {0}'.format(output1))
+        self.assertEqual(output1, '[0,1,2,3]', 'Expected [0,1,2,3] in first template, got {}'.format(output1))
 
     def test_cache_regression_20130(self):
         t = Template('{% load cache %}{% cache 1 regression_20130 %}foo{% endcache %}')
diff --git a/tests/utils_tests/test_html.py b/tests/utils_tests/test_html.py
index ff9d7f4ac0..4023434101 100644
--- a/tests/utils_tests/test_html.py
+++ b/tests/utils_tests/test_html.py
@@ -43,7 +43,7 @@ class TestUtilsHtml(TestCase):
 
     def test_format_html(self):
         self.assertEqual(
-            html.format_html("{0} {1} {third} {fourth}",
+            html.format_html("{} {} {third} {fourth}",
                              "< Dangerous >",
                              html.mark_safe("<b>safe</b>"),
                              third="< dangerous again",
diff --git a/tests/utils_tests/test_numberformat.py b/tests/utils_tests/test_numberformat.py
index 80f222d955..84ba378e46 100644
--- a/tests/utils_tests/test_numberformat.py
+++ b/tests/utils_tests/test_numberformat.py
@@ -28,13 +28,13 @@ class TestNumberFormat(TestCase):
         self.assertEqual(nformat('-1234.33', '.', decimal_pos=1), '-1234.3')
 
     def test_large_number(self):
-        most_max = ('{0}179769313486231570814527423731704356798070567525844996'
+        most_max = ('{}179769313486231570814527423731704356798070567525844996'
                     '598917476803157260780028538760589558632766878171540458953'
                     '514382464234321326889464182768467546703537516986049910576'
                     '551282076245490090389328944075868508455133942304583236903'
                     '222948165808559332123348274797826204144723168738177180919'
-                    '29988125040402618412485836{1}')
-        most_max2 = ('{0}35953862697246314162905484746340871359614113505168999'
+                    '29988125040402618412485836{}')
+        most_max2 = ('{}35953862697246314162905484746340871359614113505168999'
                      '31978349536063145215600570775211791172655337563430809179'
                      '07028764928468642653778928365536935093407075033972099821'
                      '15310256415249098018077865788815173701691026788460916647'
diff --git a/tests/utils_tests/test_os_utils.py b/tests/utils_tests/test_os_utils.py
index 7e6c74b3da..e1bc3e5d83 100644
--- a/tests/utils_tests/test_os_utils.py
+++ b/tests/utils_tests/test_os_utils.py
@@ -17,7 +17,7 @@ class SafeJoinTests(unittest.TestCase):
         drive, path = os.path.splitdrive(safe_join("/", "path"))
         self.assertEqual(
             path,
-            "{0}path".format(os.path.sep),
+            "{}path".format(os.path.sep),
         )
 
         drive, path = os.path.splitdrive(safe_join("/", ""))